ABSTRACT
Recognizing the complexity and continuum nature of thought disorder phenomena, Johnston and Holzman (Johnston, 1975; Johnston and Holzman, 1979) developed the Thought Disorder Index (TDI) as a summary measure of pathological thinking. First introduced in 1975 as part of an unpublished doctoral dissertation, (Johnston, 1975), the TDI later formed the basis of a book entitled Assessing Schizophrenic Thinking (Johnston and Holzman, 1979), which presented empirical support for the reliability and validity of the TDI.
